The present invention relates to the construction of masonry “cavity” walls of the type that have an outer wall structure formed from masonry components set in mortar, and an inner wall structure that is separated from the outer wall structure by an air space cavity from which moisture is vented by weep vent passages formed through lower portions of the outer wall structure. More particularly, the present invention relates to the provision and use of a foldable mortar and debris collection device for insertion into lower portions of the air space cavity of masonry cavity walls for preventing the obstruction of drainage weep vent passages by wet and dry mortar droppings and sizable construction debris during and after construction.
So-called “masonry cavity walls” have outer wall structures formed from masonry elements such as bricks, concrete blocks, tiles, stones and the like that are set in mortar, and inner wall structures that are separated from the outer wall structures by a space of typically about one to about five inches. The space between the inner and outer wall structures is referred to as an “air space cavity” or, more simply, as a “cavity.” If the space between the inner and outer wall structures of a masonry cavity wall is two inches, the air space cavity is said to have a “width” of two inches. Masonry cavity walls typically have cavities that range in width from about one inch to about five inches, with a range of about one inch to about three inches being most common.
As is well known, moisture tends to form in the air space cavity of a masonry cavity wall, and tends to collect in lowermost portions of the cavity. If collected moisture is allowed to remain within the air space cavity, damage may be caused as adjacent and nearby construction materials become damp. This damage may range from cosmetic discoloration to rot, disintegration and structural weakening that may require costly repair and replacement.
Providing weep vent passages that extend through the outer wall structure, especially through lowermost portions of the outer wall structure, can do much to ventilate and to drain moisture from the air space cavity of a masonry wall. However, weep vent passages will not perform their intended function if they are obstructed, or if moisture is blocked from moving through lower and lowermost portions of the air space cavity to reach the weep vent passages.
To prevent mortar and construction debris from collecting in lowermost portions of masonry wall cavities where it may obstruct or block moisture from entering and discharging through weep vent passages intended to drain moisture from lowermost cavity portions, a variety of types of collectors and deflectors have been proposed for insertion into air space cavities. In U.S. Pat. Nos. 2,705,887 and 5,845,455, for example, V-shaped troughs of solid construction are disclosed for collecting mortar and debris at locations above where weep vent passages open into lower portions of the outer wall structures of masonry cavity walls.
Other proposals, such as those disclosed in U.S. Pat. Nos. RE-36,676, 6,256,955, 6,023,892, 5,937,594, 5,598,673, 5,343,661 and 5,230,189, employ mats formed from polymer filaments that twist and turn like the filaments of furnace air filters—single-thickness mats that are inserted into lower portions of the air space cavities of mortar cavity walls to collect or deflect mortar droppings and debris while also defining networks of passages through which moisture can travel downwardly toward weep vent passage openings for discharge through the weep vent passages. The single-thickness mats proposed by others do not utilize mat elements that are connected by flexible hinge formations, nor do these single-thickness mats “unfold” after being inserted into masonry wall cavities.
Some open-space, filament-formed, mat-type mortar and debris collector proposals call for the mats to have thicknesses that substantially equal the widths of the air space cavities into which these mat-type collectors are inserted, so that mortar and debris will be prevented from passing downwardly alongside the mats, and thus will be prevented from accumulating adjacent weep vent passage openings. Providing mats that have the same thicknesses as the cavities into which they are inserted can present difficulties inasmuch as these cavities are not all of the same width, and, in fact, may vary considerably in width. If a mat is too thick to fit into a particular cavity, forcing it into the cavity can cause unwanted displacement of newly laid masonry elements.
Some open-space, filament-formed, mat-type mortar and debris collector proposals call for mats that are substantially thinner than the widths of the cavities in which they are inserted, with the mats being intended to lean either forwardly or rearwardly within the cavities so as to bridge the widths of the cavities to thereby catch mortar droppings and construction debris while simultaneously permitting moisture to pass therethrough. The use of thin, single-thickness mats that lean or are otherwise positioned to bridge the widths of the air space cavities in which they are installed has not proved to be adequately reliable. Some of these mats fail to support the weight of accumulated mortar droppings and debris. Some are found to move out of their installed positions when struck by mortar droppings or construction debris, which has been found to permit other mortar droppings and debris to pass by the mats and come to rest in positions where they block or obstruct weep vent passage openings.